ECOLOGICAL CONNECTIONS AFFECT DISEASE RISK

Lizards are a primary host for Ixodes pacificus ticks during the nymphal stage of their life.  Engorged tick nymphs can often be seen attached to the neck area of lizards caught in the wild.  Ticks and lizards are so associated with each other that removing lizards from an area can lead to a drastic drop in tick population as well, according to a 2011 study by Swei et al.1  However, some lizards such as the Western Fence lizard and the Southern Alligator lizard can also combat Lyme Disease because a protein within the lizard blood will kill the infectious bacteria Borrelia burgdorferi2.  After the tick nymph is done feeding, it is cleared of the bacteria and so that it does not transmit it while it feeds as an adult.  This may be one reason that Lyme Disease is much less prevalent on the west coast than the east coast of the United States where the lizard species lack the protein. 

1. Swei, A., C.J. Briggs, R.S. Lane, R.S. Ostfeld. 2011. Impact of lizard removal on the abundance and infection prevalence of a Lyme disease vector. Proceedings of the Royal Society B, 278 (1720): 2970-2978.

2. Lane, Robert S. and G.B. Quist. 1998. “Borreliacidal factor in the blood of the Western Fence Lizard (Sceloporus occidentalis).”  Journal of Parasitology 84:1 (February 1998): 29-34.